Molds



April 12, 1960 Filed Aug. 28, 1957 FIG. I

J. w. KNIGHT 2,932,075

MOLDS 2 Sheets-Sheet 1 FIG. 2 62 A 60 f 2 5 INVENTOR Joseph W Knight April 12, 1960 J. w. KNIGHT 2,932,075

MOLDS Filed Aug. 28, 1957 2 Sheets-Sheet 2 FIG. 7

B m 72 70 FIGS 8 INVENTOR Joseph W. Knight BY 46 46 Ana/2 wig! 38 v ATTORNEY} MOLDS Joseph W. Knight, Winter Park, Fla.

Application August 28, 1957, Serial No. 680,777

'5 Claims. (Cl. 25-118) This invention relates to improvements in molds, and more particularly to improvements in forms and molds for casting concrete pipe. 7

The primary object of this invention is the provision of an extremely strong form possessing a high degree of rigidity that will retain its shape even though extremely great pressures may be exerted upon the form. In the past quite a variety of concrete molds have been advanced, however, these molds have usually been made of flexible steel sheets and flexure of the sheets was necessary in order to contract or expand the mold; With the advent of high frequency concrete molding, increasing the density of the concrete, extremely high pressures have been built up within the molds, which has resulted in the deformation of molds made from flexible steel sheets. It was impossible, in the past, to reinforce the flexible steel sheets making up the. mold, as this would interfere with the flexure of the sheets, however, reinforcing may be easily applied to my mold. without interfering with its operation.

A further object of this invention is the provision of a mold having a plurality of sections forming a unitary structure having the sections thereof movably mounted with respect to each other so that the. mold may be either expanded or contracted without the removal of. any parts of the mold.

A further object is the provision of a mold comprising a plurality of sections that are not required to flex or change shape upon expansion or contraction of the mold.

A further object is the provision of a mold comprising a plurality of sections having at the point of juncture of the sections a novel sealing means which also serves as a lubricating means, between the movable sections, facilitating the movement of the sections with respect to each other.

A further object of. this invention is the provision of a mold having a novel expansion and contraction means wherein the force which is applied in expanding or contracting the molds will, have an opportunity to attain momentum before it is required to exert any power in the expansion or contraction of the mold.

Other objects and advantages of this invention will be apparent during the course of the following detailed description.

In the accompanying drawings, forming a part of this specification, and wherein, similar reference characters designate corresponding parts, throughout the several views:

Fig. 1 is a side elevation ofan exterior mold in operative position.

Fig. 2 is a side elevation of the exterior mold in. an expanded position for removal from about the molded product.

Fig. 3 is a top plan view of the exterior mold, partly exploded and partly in section.

Fig. 4 is, an enlarged fragmentary side elevation of the mechanism for expanding. and contracting, the. mold.

States Patent ice Fig. 5 is a vertical sectional view taken substantially on the line 5-5 of Fig. 4.

Fig. 6' is a longitudinal cross sectional view showing both the internal and external mold in molding position.

Fig. 7 is a longitudinal sectional view showing both the internal and external molds in contracted and expanded relationship respectively, for removal from about the molded product.

Fig. 8 is a top plan view of the internal mold, partly exploded and partly in section.

Fig. 9 is a transverse sectional view taken substantially on the line 9-9 of Fig. 6.

In the drawings, wherein for the purpose of illustration are shown preferred forms of internal and external molds, the letter A may generally designate an external mold; B an internal mold; C mold expansion means of the external mold A; D mold contraction means for the internal mold B; E sealing means which provides a fluid tight seal for the molds A and B; and F lever means for actuating the means C and D.

The external mold A generally comprises a casing having side sections 10 and 11, shown in Fig. 3 as being of an arcuate configuration, but which may be of any desired shape. If additional rigidity is required of the casing a plurality of ribs 13 may be secured externally of the side sections 10 and 11 as illustrated in Figs. 1 and 2. The side sections may comprise a single unit, or they may be divided into a plurality of side sections, however, I have found that the optimum results are obtained when two side sections are utilized.

The side sections 10. and 11 have side edges 16 and 17, respectively, convergent toward each other at the uppermost portions thereof and divergent away from each other at the lowermost portions thereof, forming a pair of longitudinal diverging planar surfaces. These side sections 10 and 11 are so designed that when the side edges 16 and 17 are spaced apart and the mold expansion means C placed there'oetween, the means C and side sections 10 and 11 form a symmetrical mold.

Guide means 19 are provided adjacent and overlapping the side edges 16 and 17. The guide means 19 preferably comprises guide rails 21 secured to the side sections 10 and 11 and having a portion thereof overlapping the side edges 16 and 17 for substantially their entire length. The guide rails 21 are provided, upon the face thereof which overlaps the side edges 16 and 17, with a longitudinal groove 23 which forms a sealing means E and provides for lubrication between the side sections 10 and 11 and the mold expansion means C, as will be subsequently described. A grease fitting 24, leading into the grooves 23, may be provided for the injection of a lubricant into the grooves 23.

Secured upon one side edge 25 of the guide rails- 21 are spaced wedge means 26. The spaced wedge means 26 comprise a block 28 having the uppermost portion thereof tapered inwardly, as at 29, toward the side edge 25. The wedge 28 is provided at the lowermost portion thereof with a longitudinal slot 39 which receives a bolt 31 which secures the wedge 28 to the guide rail 21. Secured to the side edge 25 of the guide rail 21 and spaced below the lowermost edge of the wedge 28 is a block 33. This block 33 receives a bolt 34, threaded therethrough, which abuts against the lowermost edge of the wedge 23. Upon loosening of the bolt 31 and rotation of the bolt v34, thewedge 28 may be longitudinally moved along the side edge'ZS, the movement therealong being limited by the length of the slot 30, thus permitting longitudinal adjustment of the wedge 28. The operative relationship of these wedges to. the mold will be subsequently described.

The: mold expansion means C may generally comprise panel sections 38 and panel supporting means 39. The panel sections 38 may be provided with reinforcing ribs 40 similar to the ribs 13 of the side sections 10 and 11. The panel sections 38, together with the side sections 10 and 11 form a symmetrical mold. The panel'sections 38 have side edges 41 and 42, convergent at the uppermost portion thereof and divergent at the lowermost portion thereof, which are designed to parallel and abut the side edges 16 and 17 respectively of the side sections 10 and 11.

The outermost face of the panel sections 38 abuts against the overlapping portion of the guide rails 21, and longitudinally covers the grooves '23. It will thus be apparent that when a lubricant is injected through the fitting 24, into the grooves 23, that the same will fill the longitudinal grooves 23, thereby providing a lubricant which permits the facile movement of the panel sections 38 with respect to the side sections 10 and 11 and also provides a fluid-tight seal between the side sections 10 and 11 and the panel sections 38, thereby providing a fluid-tight mold.

Secured upon the outermost surface of the panel sections 38, and adapted to abut against the innermost side edges 45 of the guide rails 21 are guide rails 46. These guide rails 46 form guide means 47 which cooperate with the guide means 19 in forming a trackway along which the panel sections 38 may move with respect to the side sections 10 and 11.

The panel supporting means 39 generally comprises a plurality of bars which extend transversely across the panel sections 38. These bars 50 are secured to the rails 46 of the panel sections 38 as by bolts 52. Secured at the outermost ends of the bars 50, and adapted to abut against the side edges 25 of the guide rails 21 are anti-friction roller means 55. The relationship of the anti-friction rollers 55, and the wedges 28 is not critical for the expansion of the outer mold A, but is critical for the contraction of the inner mold B, and therefore this relationship will be subsequently described when describing the operation of the inner mold B.

The lever means F may generally comprise a pair of arms 60, connecting linkage 61 and a connecting rod 62. The arms 60 are pivotally secured upon the outermost face of the guide rails 21, as shown in Fig. 4, and extend downwardly and inwardly to a connection with the connecting rod 62. The connecting linkage 61 is pivotally secured at one end thereof to the arms 60, and at the other end thereof to the guide rail 46. This linkage 61 may be longitudinally adjustable so that it may be lengthened or shortened, thereby governing the connection of the linkage 61 to the guide rails 46. The arms 60 are provided at their lowermost ends thereof with a slotted opening 63 through which is secured the connecting rod 62. This slot 63 is provided so that upon initial upward movement of the connecting rod 62 the arms 60 will not be moved, thus enabling the lifting force to gain a slight momentum before force is exerted on the arms 60, providing a lag in the operation of the arms 60 and thus facilitating the movement thereof. The connecting rod 62 may be provided with an eye 64 at the uppermost end thereof for receiving any suitable lifting connection. a

Each of the panel sections 38 are provided with lever means F although this has not been shown in Fig. 3 for the purpose of clarity.

The assemblage and operation of this mold is as follows:

The panel sections 38 are interfitted between the side sections and 11, and the panel supporting means 39 are secured to the panel sections.

A lubricant is then injected through the fittings 24 into the longitudinal grooves 23. The panel sections .are then lowered into the position as shown in Fig. 1,-with the roller means 55 riding up upon the surfaces 29 of the wedges 28, securely holding the side edges 16 and 17 of the side sections 10 and 11 in close abutment with the side edges 41 and 42 of the panel sections 38, forming a continuous, symmetrical mold having a smooth inner surface. The material to be molded is then placed within the mold and any desired operation, such as high frequency vibration of the mold may take place in order to form the material in the desired strength and thickness. After the material to be molded has set to the desired degree the connecting rods 62 are then lifted, which through the arms 60 and the linkage 61 raises the panel sections 38 to the position as shown in Fig. 2.

. Upon upward movement of the panel sections the side edges 41 and 42 of the panel section 38 will expand the mold by increasing the space between the side edges 16 and 17 of the side sections 10 and 11, forcing the side sections 10 and 11 apart and increasing the internal diameter of the mold. The interior surface of the mold is thereby expanded from surface contact with the molded material and the mold may be easily lifted from about the molded material.

The inner mold B is constructed substantially identical to the outer mold A, and therefore the various parts of the inner mold B have been given the same reference characters as the outer mold A, with the addition of a prime indicia in order to differentiate between the inner and outer molds.

The primary differences between the inner mold B and the outer mold A is that the side edges 16' and 17' of the side sections 10' and 11' are divergent at the uppermost portions thereof and convergent at the lowermost portions thereof and the side edges 41 and 42' of the panel sections 38 are likewise reverse from that utilized in the mold A, in that they are divergent at the uppermost portions thereof and convergent at the lowermost portions thereof, paralleling the side edges 16 and 17' of the side sections 10' and 11'. Whereas in the form A, the panel supporting means 39 was positioned externally of the mold, providing a smooth mold interior, in the form B the panel supporting means 39' are positioned internally of the mold, providing a smooth mold exterior. A cover 70 may be provided over the internal mold B, thus preventing any of the material to be molded from falling within the internal mold B. When this cover 70 is utilized the connecting rod 62 may be secured to the lowermost surface of the cover 70 and an eye 72 is provided upon the uppermost surface of the cover 70, so that upon the lifting of the cover 70, by any suitable means secured to the eye 72, the connecting rod 62' will be raised.

The exact relationship of the anti-friction roller means 55, with respect to the guide rails 21' and wedges 28', is of the utmost importance in the internal mold B. Whereas in the external mold A the mold was expanded by the outward pressure of the panel sections against the side sections, the internal mold B is contracted by the pressure of the anti-friction roller means 55' against the surface 25' of the guide rails 21'. The provision of the wedges 28, in this form, permit the panel sections 38' to be raised slightly before the anti-friction roller means 55' will contact the side edges 25 of the guide rails 21', thus providing a lag between the upward movement of the panel sections 38' and the pressure of the anti-friction roller means 55' against the side edge 25' of the guide rail 21'. This permits the panel sections to gain a slightbit of momentum before the inner mold is contracted.

The assemblage and operation of the inner mold B is as follows:

The panel sections 38' are interfitted between the side sections 10' and 11', with the guide rails 46' abutting one side edge of the guide rails 21'. A lubricant is inserted into the groove 23' through the fitting 24', thus providing both a lubricant for the movement of the panel sections 38' with respect to the side sections 10' and 11' and a seal between these various sections. The panel supporting means 39 are then secured to the panel section 38', securely holding the same in position.

The panel section is then moved into a position as shown in Fig. 6 and the material to be molded is placed about the internal mold B. After this molded material has set to the desired degree the cover 70 is raised, thus operating the lever means F and raising the panel section 38. The pressure of the anti-friction roller means 55' against the side edges 25 of the guide rails 21' will contract the side sections 10' and 11, thus freeing the in-' ternal mold B from surface contact with the molded material and the mold maybe removed.

Both the external mold A and the internal mold B may be used together, in molding a pipe of cementitious material, as shown in Figs. 6, 7 and 9. The joint operation of these molds in casting cylindrical pipe is the same as has been hereinbefore described. Spacers 75, which may be rods extending between the inner and outer molds, as shown in Fig. 9, may be placed between the inner and outer molds in order to secure a uniform thickness of the pipe being molded. If itis desired the connecting rods 62 and 62' may be raised at the same time and the inner and outer molds simultaneously lifted from the pipe, or the molds may be individually raised and removed.

Various changes in the shape, size and arrangement of parts maybe made'to the form of invention herein shown and described without departing from the spirit of the invention or scope of the claims.

What is claimed is:

1. In a form for molding cementitious material, the combination of a casing having spaced apart side edges defining an opening in said casing, said side edges being divergent at one end thereof and convergent at the other end thereof; a panel section movably mounted in and bridging the opening in said casing, said panel section having divergent and convergent side edges complementary to the divergent and convergent side edges of said casing; guide rails secured to said casing, each of said guide rails having opposite side edges and being secured to said casing so that one of the side edges of each of said guide rails overlaps a portion of said panel section; a bar member secured to said panel section, said bar member extending outwardly from the sides of said panel section and over said guide rails, said bar member abutting said guide rails and holding said panel section in overlapped position with respect to said guide rails; anti-friction roller means secured to the outermost ends of said bar member, said roller means engaging the side edges of said guide rails opposite the side edges thereof that overlap a portion of said panel section and holding the complementary side edges of said panel section and said casing in proximate abutment; and means for movement of said panel section with respect to said casing.

2. The combination as specified in claim 1 wherein said guide rails have secured thereto wedge means supporting when said panel section is moved with respect to said casing.

3. A rigid form for the molding of cementitious material comprising a plurality of side sections having spaced apart side edges divergent at one end thereof and convergent at the other end thereof, a plurality of panel sections movably interfitting between and bridging said side edges, said panel sections having side edges that are each in complementary abutment with a side edge of one of said side sections, the interfitting relationship of said side sections and said panel sections forming a mold having a smooth face, rails secured to said side sections parallel to the side edges of said side sections, said rails having opposite side edges one of which overlaps a portion of a panel section, rails secured to said panel sections abutting the overlapping side edges of said first mentioned rails, bar members secured to said panel sections and overlapping said first mentioned rails, roller means secured to said bar members, said roller means engaging said first mentioned rails opposite the abutment of said first and second rails, and lever means for the movement of said panel sections with respect to said side sections.

4. A mold comprising a casing having spaced apart side edges, said side edges convergent at one end thereof and divergent at the other end thereof, rails secured to .said casing, said rails having opposite side edges one of which overlaps a side edge of said casing, a panel section movably mounted between and bridging the side edges of said casing, said panel section having side edges complementary with the side edges of said casing and abutting the overlapping portion of said rails, rails secured to said panel section and abutting one side edge of said first mentioned rails, bar members secured to said panel section abutting the face of said first mentioned rails opposite the first mentioned abutting portion of the panel section, rollers secured to said bar members, each of said rollers abutting the side edge of one of said first mentioned rails opposite the side edge thereof in abutment with said second mentioned rails, and a lever pivotally mounted upon said casing for moving said panel section with respect to said casing, the actuation of said lever in one direction contracting the mold and the actuation of the lever in the other direction expanding the mold.

5; A mold as described in claim 2 wherein said wedge means are longitudinally adjustable along said first mentioned guide rails, permitting regulation of the lag.

References Cited in the file of this patent UNITED STATES PATENTS 892,592 Helm et al July 7, 1908 1,346,640 Dewey July 13, 1920 1,632,899 Hutchins June 21, 1927 2,733,495 Lucas Feb. 7, 1956 2,799,073 Bergling et al July 16, 1957 2,805,462 Chandler et a1 Sept. 10, 1957 2,828,526 Blasius et a1. Apr. 1, 1958 FOREIGN PATENTS 226,604 Germany Oct. 6 1910 

